All refresher kits at any strength offered on this site of Nite White and Day White includes ACP )for Sensitivity) and are a popular at-home whitening gel. Thanks to the safety of its ingredients and its manufacture who is by Discus Dental, the original maker of the venerated ZOOM! one-hour tooth whitening system, so you know our products are the best offered in the dental field today! Phillips ZOOM ACP kits are a clinical-grade tooth whitening gel of 16% or 22% carbamide peroxide. Compared against the range of take-home tooth whitening gels, 22% is a medium strength tooth whitening gel that is an excellent option for sensitive mouths. It is typically worn for 1 hour. Discus Dental manufactures the only take-home whiteners that combine amorphous calcium phosphate (ACP) with potassium nitrate and fluoride, providing enhanced whitening results. This ACP formulation is clinically proven to rebuild enamel, reduce tooth sensitivity by 30% and adds luster by re-mineralizing teeth and reducing fade back. Phillips ZOOM is approved and accepted by the American Dental Association. Phillips ZOOM is also the next generation of the Nite White Excel line of tooth whiteners. Each shipment includes three 2.4 mL syringes of gel and three application tips. Phillips ZOOM products come in double-barreled syringes. Each barrel houses a separate bleaching agent. Special syringe mixing tips activate these ingredients by blending them upon application to your tooth whitening trays. This keeps the gel fresh for approximately 12 months, according to the manufacturer. We have proof that is last up to 5 years or more.